SDR# (read SDR Sharp) is a high performance Software Defined Radio application. It is written in C# with both object design correctness and performance in mind. The project started as a simple proof of concept program to get hands into DSP techniques and has evolved to what it is today: A fully featured SDR capable of handling samplerates from kHz level soundcards up to multi hundred MHz dedicated samplers, thanks to its multi-core architecture. The source code is disclosed for educational purposes and for reference to those who want to build their own plugins.
Do you still think C# is too slow for DSP? Give it a try and compare with some Intel’s IPP powered concurrents out there.

SDR# reading a 2MSPS file recorded using RFSPACE's SDR-IP


746 Responses to Welcome

  1. phidyos says:

    First of all, nice job guys! This software is amazing ! I work for the French Air Force, on navaids. Do you think a software like this could decode signals from Tacan or VOR? Finally, I just found a little bug : if you run SDR# on a system with multiple screens, the options on the right are invisible (contrast, zoom). Just a problem with detecting resolution I suppose.

    • Youssef says:

      These should be (easily?) demodulated, indeed. Being French myself I’ll be glad to provide some help with it.
      The display bug has been identified and will be worked out soon. It’s all about the screen’s DPI.

  2. N says:

    Hi All just letting you know I have another up converter design on Make a at

    Although I designed it to work with my Yaesu FRG 9600 it wiil work with any SDR giving coverage of HF on a VHF system. Just have a look.

    All the best and 73 de Nick G0CWA

  3. FunkyBurger says:

    First of all thank you very much for the great SDR# Software and for sharing the code. Looking at the code (especially DSP Sources) is like watching great Drummers on Youtube :) It’s very inspiring and blows my mind!
    Now to my reuqest:
    I created a Scanner plugin for SDR#. To get the scanner working I need the current Signal Level of the tuned frequency. Therefor i calculte the Level out of the FFT Spectrum.
    public float RxLevel
    double delta = _vfo.Frequency / (_streamControl.SampleRate / _fftBins);
    int val = (int)_fftSpectrumPtr[_fftBins / 2 + (int)delta];
    return val;
    For now, I added this as a public property to ISharpControl/MainForm.cs
    Now I have some questions:
    1) Is the RxLevel calculation correct? Is there a better way to get the signal level?
    2) Could you overtake the property to the SDR# main line software? Or is there perhaps a better way, e.g. implementing a Hook to process FFT data in a plugin?
    3) Is it possible to use a branch in the svn repo at for plugin development?
    Thanks a lot for your response!

  4. BillPretty says:

    The Zadig file “installer_x86.exe” is reported to have the following virus:


    Anybody else had this problem ??

  5. BillPretty says:

    Also the sdr-install.bat didn’t work either.

    I can post the error message, but basically the program never started.

  6. BillPretty says:

    Avira antivirus software reports that Zadig contains a virus and won’t let it run.

    I tried another PC without Avira and Zadig doesn’t appear to work properly.
    I never get the option to change or update the driver to RTL2832xx .

  7. Tekla says:

    My Wish List:
    Squelch option for ALL bands especially HF.
    Add k8gjl frequency manager + scanner dll from reddit.
    Green S9+40 bargraph right of vfo display.

  8. midimagic says:


    I have SDR working on my main PC (win XP SP2) but want to install it on my laptop. The laptop has Win XP SP2 but it will not install. When I run the SDRSharp.exe it comes back with “The application failed ot initialize properly (0xc0000135) Click on OK to terminate the application.
    I did try it on another old XP laptop but that did install but kept crashing.
    Do I need anything like .net installed first?

  9. darealal says:

    is there any way to implement a frequeny- or channelscan ? Maybe via the Frequency Mananger Plugin ? ( I dont know if the tuners r fast enough) or maybe a set of priority frequencys in the “current Spectrum” with lower or higher priority ?
    (Sorry my bad english and i hope u know what i mean :)

    Greats from Germany

  10. nu6x says:

    Help Please……………
    I recently setup a Terratec T Stick PLUS wid SDRSHARP. It is bascily working but with very low sensitivity and a high noise floor. I don’t know what to expect. The noise floor grass is aroung -60 to -50 even with no antenna connected. I used a USB extension cable to separate the stick from any computer generted noise but no improvement. The end result is I can only hear the very strongest FM stations using the supplied antenna. On the 2M band using a good outdoor antenna, I can hear only the strongest repeaters using an outdoor beam and they are only 20 db above the noise. The same repeater is full quieting using a HT and a rubber duckie……Is this Normal???
    Thanks….Mark NU6X Sedona,AZ

    • lodenkabat says:

      Adjust the tuner gain NOT auto, and manualy not to maximum!
      I have an dongle with R820T, and was also this problem.

      73 de Pista HA1FV

      • nu6x says:

        Thanks Pista. I had exprimented with the RF Gain. I have auto off and I found the best setting was around 15 db of gain. My above observations where with these settings. I just can’t get the noise floor below below -60 to -50.I’m wondering if my Terratec T Stick is at fault….Thanks, Mark NU6X

    • W6KAP says:

      Have you gone into configuration and increased the RF Gain?

    • W6KAP says:

      Sorry, just noticed you had already addressed that. My noise level is also -50 to -60db but signals are strong on the R820T tuner. I have compared 2 meter repeaters between the dongle and my IC706mkIIg and I don’t find much difference.

      The tuner has an LNA in front of it and they can be easily damaged. It doesn’t sound damaged if you are receiving signals 20 db quieting. If damaged, you probably wouldn’t hear anything much. Which tuner is in the Terrastick?

      • Hombre says:

        I have R820T tuner and noise level is about -105 db on all frequencies when use RTL Settings with Tuner AGC marked.
        If I get Tuner Gain AGC manualy noise level is about -70 dbm

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